Democratic Michigan Congressman and Senate candidate Gary Peters refused to sell his stock in the substance petroleum coke (petcoke), despite the fact that he has called petcoke “dirtier than the dirtiest fuel” and launched a public campaign to highlight the evils of a petcoke buildup in the area around the Detroit River.

Peters owns $19,000 in stock in the French oil company Total S.A., which produces petcoke, among other things. Peters’ 2014 Republican Senate opponent, Terri Lynn Land, has been hammering Peters on the investment.

“Am I going to sell it? I have no plans of it, no,” Peters said in comments Monday to The Detroit News. “It is an investment in the fourth largest oil company in the world. It has nothing to do with the Detroit situation.”

Peters had previously been ahead of Land by seven to nine points. Real Clear Politics ranks the race as leaning Democratic, but with 44 days until the election and Peters continuing to slip in the polls, the race is still very much in play.